- First Name
- Mar 29, 2020
- Reaction score
- Melbourne, Australia
- Subaru STI, KTM450EXC
The rate of heat loss or gain depends on . . . Q = M x C x (Temp final - Temp Initial)The rate of radiative heat loss or gain depends on . . . . .
But the rate of temperature change per unit of heat absorbed depends on the material. Mild steel and stainless steel have specific heats that are pretty close. 510.8 and 502.4 j/(kg-K) respectively (304 stainless) and thus both will absorb and retain heat for about the same time if the same thickness and painted the same color.
Can't compare exactly cos Tesla / Spacex haven't revealed details of their Stainless Steel recipe, but its reasonable to assume maybe 7% greater density for Stainless Steel than mild steel for a regular body panel.
As you mention, The specific heat j/kg/k is similar, but the mass is more than 5 times greater for Stainless Steel, just from the thickness, 0.6mm vs 3mm.
That is a significant difference in heat capacity / heat retention.
Temp change will be slower, but the retention of heat, and the opportunity for harm to the touch, and for a challenge to the HVAC will be far greater.